A lot of our ideas about what we can do at different ages and what age means are so arbitrary — as arbitrary as sexual stereotypes. I think that the young-old polarization and the male-female polarization are perhaps the two leading stereotypes that imprison people. The values associated with youth and with masculinity are considered to be the human norms, and anything else is taken to be at least less worthwhile or inferior. Old people have a terrific sense of inferiority. They’re embarrassed to be old. What you can do when you’re young and what you can do when you’re old is as arbitrary and without much basis as what you can do if you’re a woman or what you can do if you’re a man.

This notion of investigation offers an alternative to confession. Its goal isn’t sympathy or forgiveness. Life is not personal. Life is evidence. It’s fodder for argument. To put the “I” to work this way invites a different intimacy—not voyeuristic communion but collaborative inquiry, author and reader facing the same questions from inside their inevitably messy lives.

Sadness can be legitimately problematic, absolutely. If your sadness comes from seemingly no place or even an obvious place but keeps you from participating in life or enjoying anything and refuses to abate no matter how long you go on letting it express itself, you of course can’t keep living like that. But culturally, we aren’t allowed to be sad even for a little while. Even when it’s perfectly sensible. Even when, sometimes, we need it.

[E]volution actually happened. Biology is incomprehensible without it. There aren’t really two sides to all these issues. Climate change is happening. Vaccines really do save lives. Being right does matter—and the science tribe has a long track record of getting things right in the end.

…

It’s their very detachment, what you might call the cold-bloodedness of science, that makes science the killer app. It’s the way science tells us the truth rather than what we’d like the truth to be. Scientists can be as dogmatic as anyone else—but their dogma is always wilting in the hot glare of new research. In science it’s not a sin to change your mind when the evidence demands it. For some people, the tribe is more important than the truth; for the best scientists, the truth is more important than the tribe.

[S]ome failure in life is inevitable. It is impossible to live without failing at something, unless you live so cautiously that you might as well not have lived at all – in which case, you fail by default.

Failure gave me an inner security that I had never attained by passing examinations. Failure taught me things about myself that I could have learned no other way. I discovered that I had a strong will, and more discipline than I had suspected; I also found out that I had friends whose value was truly above the price of rubies.

The knowledge that you have emerged wiser and stronger from setbacks means that you are, ever after, secure in your ability to survive. You will never truly know yourself, or the strength of your relationships, until both have been tested by adversity. Such knowledge is a true gift, for all that it is painfully won, and it has been worth more than any qualification I ever earned.